print('定义字典对象zhang');
zhang={'name':'张三','age':21,'phone':13712344567};
print('定义字典对象li');
li={'name':'李四','age':28,'phone':13787654321,'friend':zhang}
print('设置zhang[\'friend\']=li\n');
zhang['friend']=li;
print('zhang:',zhang,'\n');
print('li:',li,'\n');
print('李四的朋友的年龄：li[\'friend\'][\'age\']=',li['friend']['age']);